rad bio chapter 8/9 test 4

Prodromal stage

• Occurs within hours of the exposure

• Is the first stage of ARS

• N &V, diarrhea, fatigue, leukopenia; may last a few hours or a few days

Latent period

Follows the prodromal stage; lasts approximately 1 week; no visible symptoms; the recovery or lethal effects begin here

Manifest illness

Folks the latent period; specific syndrome type symptoms occur

Death or recovery

The final stage; outcome decided in the latent period

Hematopoietic syndrome

Occurs when the whole body receives a dose between 1 and 10 Gy (100 or 1,000 rad); manifest symptoms include decreased RBC (red blood count) and WBC (white blood count) and platelet count; if death occurs, it will occur 6-8 weeks after the exposure

Gastrointestinal syndrome

Occurs at a threshold dose of approximately 6 Gy (600 rad); manifest symptoms include severe n & v, diarrhea, and loss of appetite, in addition to those symptoms associated with the hematopoietic syndrome; if death occurs, it will occur within 3-10 days after the exposure

cerebrovascular syndrome

Occurs when the CNS receives doses of 50 Gy (5,000 rad) or more of ionizing radiation; the person will die within hours or 2-3 days f the exposure; manifest symptoms include disorientation, shock, ataxia, brain edema, loss of equilibrium, seizures, meningitis, respiratory distress, and coma… in addition to those symptoms from the lesser two syndromes

Cancer

Long term effect

Chromosome damage

Short term effect

Epilation

Short term effect

Depressed hematologic count

Short term effect

Cataracts

Long term effect

Genetic mutations

Long term effect

Radiodermatitis

Short term effect

LD 50/30

The whole body dose of radiation that can be lethal to 50% of the exposed population within 30 days

LD 50/60

The most accurate measure for human survival than any shorter period

What is the lethal dose 50-30 radiation dose for adult humans?

3.0 to 4.0 Gyt (300 to 400 rads)

which part of the alimentary canal is most severely or adversely affected by high radiation doses?

Small intestine (a lot of intestinal undifferentiated crypt cells)

If a human being experiences a biologic effect from exposure to a high dose of radiation that occurs within minutes, hours, days, or weeks of the exposure, what kind of an effect is this?

Early somatic effect (short term effect)

If the effect occurs months or years following the exposure, what kind of an effect is it?

Late somatic / late genetic / late period

which of the following will increase cellular radiosensitivity?

• Undifferentiation

• Immaturity

• non specialized

• High reproductive

• Rapid extended cellular division

• Presence of oxygen

• High LET radiation

what dose is one that we say no dose of radiation is ever 100% safe?

Non threshold

if you are safe up to a certain point

Threshold

all life forms are most vulnerable to radiation during what stage of development?

Embryonic

What trimester in a human pregnancy is the one in which irradiation of the fetus is the most dangerous?

First trimester

Genetic effects are seen when damaged from ionizing radiation occurs to the _____ of the sperm or the egg

DNA

What kind of genetic mutations can occur if only one parent's germ cell is damaged?

Dominant genetic

doubling dose

The radiation dose that causes the number of spontaneous mutations occurring in a given generation to increase to two times their original occurance

Doubling dose amount

1.56 Sv (156 rem)

What makes repair and recovery possible when a person is exposed to sub lethal doses of ionizing radiation?

Repair enzymes

Early somatic effects are stochastic or non-stochastic?

Non stochastic (deterministic)

Early effects directly related to the dose received that occur months or years after radiation exposure are called what?

late deterministic somatic effects

effects that have no threshold that occur arbitrarily and have a severity that does not depend on dose and occur months or years after the exposure are called what?

Late stochastic /probabilistic

What kind of dose of ionizing radiation produces early biological effects?

Large dose

Early somatic effects are called ____ radiation syndrome

Acute

o write out or list 2 causes of death from the hematopoetic syndrome

1. Infection

2. Hemorrhaging

Regardless of treatment received, a whole body equivalent dose greater than ____ are considered lethal

12 Gy (1200 rad)

which of the following is best in terms of the least amount of permanent damage to the exposed person; 30 rads per month for 12 months, or 360 rad all at once?

30 rads per month for 12 months to give the repair enzymes time to repair the cell.

list three radio sensitive tissues that suffer immediate consequences from high radiation doses

1. Skin

2. Bone marrow

3. Male and female Reproductive organs

3 skin conditions that can occur due to exposure to ionizing radiation

1. Radiodermatitis (skin erythema)

2. Desquamation

3. Epilation (hair loss)

smaller doses of radiation spread out over a period of time are called _____ doses

Fractionated

What are the most radio sensitive blood cells in the human body?

Lymphocytes

what dose of ionizing radiation as low as ____ can cause a reduction in their count?

0.25 Gy

In diagnostic imaging, the only damage noted to the hematologic system is some _____ damage to the lymphocytes

Chromosomal

what kind of curves demonstrate the likelihood of a biologic reaction to a given dose of ionizing radiation?

Dose response curves

a dose response curve that is flatter in the low dose region, and it is steeper in the high dose region, is referred to as a linear _______ curve

Quadratic

Genetic mutations, are they stochastic or non-stochastic?

Stochastic

Skin erythema is that stochastic or non stochastic?

Non stochastic

what effect occurs on a random basis and increases in likelihood as radiation dose goes up?

Probabalistic

Which one of those occur at a threshold and severity increases as radiation dose increases?

Deterministic

Which one of these severity is independent of dose received?

Deterministic

the higher the dose, the greater the probability that you will see it, but you may not see it at all. What is that one?

Probabalistic

the severity is dependent on the dose received

Deterministic

as radiation dose goes up, the chance for cancer or genetic mutation does what?

Goes up

Between stochastic and non-stochastic, which are likely to be witnessed in diagnostic imaging?

Stochastic

What is a clouding of the lens of the eye?

Cataracts

what type of procedures and medical imaging result in the highest radiation exposure to the lens of the eye?

Fluoro

What can be done to protect the eyes during the above listed procedures?

• leaded goggles

• Limit time

• Increase distance from xray source

two things that you can do to be sure that you never unnecessarily expose an embryo fetus

1. Ask LMP

2. Ask any chance of pregnancy

3. Double shield

Label the graph

1. Linear (straight line) non threshold curve

2. Linear threshold curve

3. Nonlinear threshold curve

Which curves depict a probabilistic response?

1

which curves depict a non-stochastic response?

2 and 3

which curves depict a deterministic response

2 and 3

which curves demonstrate an increase in severity of the condition as the dose goes up?

2

Which curve shows an increase in the likelihood of the condition as the dose goes up?

1

Which curve would best demonstrate cancer possibility?

1

Which curve would best demonstrate cataract severity?

3

which curve demonstrates a safe dose?

2 and 3

people who are suffering from the hematoquetic syndrome. what kind of issues will they have?

• anemia

• A decrease in WBC (leukopenia)

• Decrease in platelets

• Hemorrhaging

True or false:

the greatest potential for radiation induced biological damage, exists when you have large doses of densely ionizing, high LET radiation

True

Is cancer a stochastic or non-stochastic effect?

Stochastic

are genetic effects stochastic or non-stochastic effects?

Stochastic

True or false:

Most diagnostic procedures result in equivalent doses less than 0.1 Seiverts (10 rem)

True

acute radiation syndrome

When you get a large dose of radiation administered over a short period of time

What is the minimum radiation exposure required to cause acute radiation syndrome?

1 Gy (100 rad)

the people who are suffering from the GI syndrome, will those people likely die?

Yes

Between oxygenated and deoxygenated cells, which are more likely to be damaged?

Oxygenated

When are the male sperm the most radiosensitive?

The immature or dividing stage

Female germ cells are the most radio sensitive when the female is?

In utero

Any dose of radiation to the gonads could cause what kind of abnormalities?

Chromosomal abnormalities which could be passed on as mutations in the offspring

True or false:

Current radiation workers are at no more risk for cancer development than any other member of the general population

True

If you get a dose below threshold, will cataracts form?

No

True or false:

The B-E-I-R 5 report states that cancers are thought to follow the linear non-threshold dose response curve while all other can be like leukemia follows the linear quadratic, non-threshold dose response curve

True

for non-threshold doses, we said no amount of radiation is ever considered what?

100% safe

True or false:

Late somatic effects can actually occur from high LET radiation exposure, and low LET

True

fetal radio sensitivity Goes up or down as the gestation progresses?

Goes down

True or false:

dominant genetic effects are more likely to be seen than recessive genetic defects

True